Laboratory mice are the most widely used research animals, and evidence-based enrichment significantly improves their welfare without compromising experimental validity.
Laboratory mouse welfare has improved significantly over recent decades through the recognition that enriched environments are both more humane and often produce more reliable research data. Mice in barren cages show abnormal stress responses that can confound experimental results. Providing nesting material, hiding tubes, and social housing (mice are highly social) improves welfare while also improving research quality. The Three Rs framework mandates continuous improvement in laboratory animal welfare, and enrichment programs represent one of the most impactful refinement interventions available. Supporting institutions committed to transparent Three Rs implementation advances both welfare and science.